Apparatus for registering printing plates



Mp-AFN.

Oct. 6, 1959 w. A. DUTTON 2,907,112

APPARATUS FOR REGISTERING PRINTING PLATES Filed Nov.- 25, 1957 4 Sheets-Sheet 1 lNVENTD/P fia/wmdfiaifom y ATTORNEYS.

1959 I w. A. DUTTON 2,907,112

APPARATUS FOR REGISTERING PRINTING PLATES Filed Nov. 25, 1957-- 4 Sheets-Sheet 2 //V l/E N TOR y ?AWK ATTORNEYS.

Oct. 6, 1959 w. A. DUTTON 2,907,112

' APPARATUS, FOR REGISTERING PRINTING PLATES Fild Nov. 25, 1957 4 Sheets-Sheet 3 w, H a; /4 ms zea -Q (Z0) 0 g we Oct. 6, 1959 w. A. DUTTON 2,907,112

APPARATUS FOR REGISTERING PRINTING PLATES Filed Nov. 25, 1957 4 Sheets-Sheet 4 W' P 39 P 3.9 fl g I l g g l 39 fiqr 39 h .740 I I C. 146 1 5 I74 r4 0 f ATTORNEYS.

APPARATUS FOR REGISTERING PRINTING PLATES lwarren A. Dutton, Dallas, Tex., assignor to Meredith Publishing Company, Des Moines, Iowa, :1 corporation of Iowa Application November 25, 1957, Serial No. 698,736

9 Claims. (Cl. 33-1845) This invention relates to an apparatus for registering printing plates used in multi-color printing. In conventional four color printing a series of four plates or electrotypes are used. Each plate prints a different color, usually black, yellow, red and blue, one over the other. For

fine quality work it is imperative that the picture or impression printed by each plate be in precise alignment or registration With the others.

The object of this invention is to provide an apparatus for applying scribe marks on a set of printing plates through the combination of optical alignment and mechanical movements, said marks matching with guide lines on the surface of the printing cylinder or carrier to which the plates are secured.

Another object is to provide apparatus of this type adapted to position and mark one plate, referred to as the reference plate, and subsequently register one or more color plates in succession using the first one for reference purposes.

Another object is to provide an apparatus which utilizes an optical viewer for registering color plates with the reference plate by superimposing corresponding images from the surface of each plate. Still another object is to provide an apparatus of this type having trimming means for trimming the edge of the reference plate which is adapted to be secured to the cylinder in contact with a stop provided therefor.

In a preferred form of the invention useful in registering plates for rotary presses, the apparatus comprises a pair of saddles mounted for radial and axial movement with respect to a rotatable shaft on which they are mounted. The reference plate is secured to one saddle and the plate to be registered therewith to the other. The viewing means consists of a pair of illuminated scanners, one mounted above each saddle and adapted to transmit a magnified image to a single ground glass viewing screen. Marking means are mounted on the frame of the machine adjacent each saddle for scribing horizontal and vertical center line marks on opposed edges of the plate mounted thereon after the plates have been optically registered.

A further object of the invention is to provide an apparatus of this kind which makes possible rapid and very accurate registration of plates, say within plus or minus 4 of an inch.

Other objects and advantages reside in the construction of the parts and the combination thereof, as will appear from the following description when read in conjunction With the accompanying drawings, in which Figure l is a front elevational view of apparatus constructed in accordance with the invention;

Figure 2 is a side elevational view of the apparatus shown in Figure 1;

Figure 3 is a sectional view taken through the main shaft showing the locking means therefor;

Figure 4 is a perspective view of an adjustable stop for holding the location of the reference plate;

Figure 5 is a front elevational view partly broken atent away showing the construction of the main shaft which carries the saddles;

Figure 6 is a section taken along the line 6--6 of Figure l;

Figure 7 is a top view of the saddles showing plates clamped thereto; and

Figure 8 is a diagrammatic perspective view of a cable and pulley mechanism for actuating the markers.

Brieflythe method of registration employed in accordance with the invention consists in three steps: '(1) setting the reference plate accurately with respect 'to markers on the machine for scribing the plate with marks that will align accurately with guide lines on the printing press cylinder; (2) optically registering the color plate with the reference plate by superimposing the identical image from each plate on a ground glass screen;'and (3 scribing both plates with horizontal and vertical scribe marks for alignment with the cylinder guide lines.

Step 1 is accomplished by bringing a predetermined reference point on the plate, for example the page number, into alignment with cross hairs or other suitable designation appearing on the screen of the optical viewer. The apparatus is so designed that when this is done the plate becomes accurately located with respect to the marking elements on the apparatus. A stop is set against the plate support so that it can be moved away and returned to the identical position after step 2 has been effected.

.Step 2 is accomplished by radially moving about the mounting shaft the reference plate, which is usually the black plate, to bring any easily-recognizable area thereon into view on the ground glass screen. The color plate to be registered with the reference plate is then moved radially and axially as required until the image of the identical area is superimposed over the image appearing on the screen from the reference plate. When the tWo images are superimposed and appear as one, the plates are in perfect registration but then must be returned as a unit to the original position of the reference plate with respect to the markers by moving back to the stop. Step 3 is then carried out by actuating themarking elements to place the scribe marks on the plates. Usually these marks correspond to axial lines scribed on quadrants about the plate cylinder and circumferential lines along the streamer centers.

Referring now to the drawings, Figure 1 illustrates an overall view of the apparatus having a bed 10 madefrom heavy steel and a pair of upright frame members 12, 14 secured thereto at either end. The main shaft 16 is rotatably mounted in bearings disposed within openings in the upright members 12 and 14. Main shaft 16 may be hollow as indicated at 17 for purposes that will become apparent hereinafter. Saddles for supporting the printing plates and orienting them with respect to the marking device on the apparatus are indicated on the drawing generally by the numerals 18 and 20. Saddle 20 is a mirror image of saddle 18 and therefore is constructed in the identical manner to saddle 18. Consequently, in the following description only one of the saddles will be described.

A carrier bar 22 is secured to the upper ends of the upright members 12, 14 and extends lengthwise of the machine parallel to the base plate 10 and the main shaft '16. The bar 22 is adapted for carrying the viewer, indicated generally by the numeral 24, above the saddles. A mounting base 40, having the same surface radius as the printing cylinder upon which the plates will ultimately be mounted, is secured near either end to the top of a pair of segments 32 and 34. A stop 36 is fixed to the front edge of the mounting base to locate the plate thereon. A series of four clamps 39 slide in T-sh aped slots 30 cut in the base 40. Hold down screws are pivotally mounted on the carrier portion of the clamp and snap down on to the surface of plate P to hold it in place (Figure 7). Any suitable clamping means may be used for-this purpose. Preferably the fe-t of the screws which contact the plate are rubber covered so the electrotype is not defaced. The segments 32, 34 have openings extending through the circular lower portions thereof which embrace the main shaft 16. The inner surface of the bearing portion of the segments is lined with a suitable bearing metal so that the segments are freely rotatable about the shaft 16 and also movable axially with respect thereto. The segments are secured together with a tie bar 60, Figure 6.

For actuating the mounting base 40 radially with respect to the shaft, I have provided a pair of stationary upright arms 42 and 43 which are clamped to the main shaft 16 at the lower ends thereof between segments 32 and 34 (Figures 1 and 6). Each of the arms 42 and 43 is diametrically split as indicated at 45 near the lower end where it encircles the shaft to form a separate arcuate piece embracing the underside of the shaft. This separate piece is secured to the other portion of the arm by means of machine screws (not shown) which are inserted through the openings 51. Consequently, the two arms 42, 43 are rigid on the shaft and will not move either radially or axially. The arm 43 terminates at its upper end in a forwardly extending angular portion having a circular opening therein which is threaded to receive shaft 54 as will be explained below. This permits axial adjustment of the saddle. Except for this feature arm 43 is identical in construction to arm 42. A block 44 is rigidly mounted between the arms 42 and 43 and carries a central roller bearing 53 in which shaft 49 is rotatably mounted. The inner end of the shaft 49 is threaded and the outer end carries a hand wheel 52 to facilitate rotating the shaft in bearing 53. Threaded end 49 engages internally threaded sleeve 46, the inner end of which is secured to a bearing 48 for the radial actuating bar 50. The bar 50 extends parallel to main shaft 16 and is fixed at either end to the segments 32 and 34. Thus when the hand wheel 52 is rotated the bearing 48 is moved inwardly or outwardly and the. bar 50 pivots the segments about the shaft to radially rotate the mounting base 40, secured thereto.

For axially adjusting the saddle I have provided a second shaft 54 which threadedly engages the threaded opening (not shown) in the upper angular portion of the fixed arm 43. The shaft 54 is pivotally mounted on roller bearings in segment 32, as indicated at 56, Figure 1, and carries a hand wheel 58 on its outer end for moving the segments in an axial direction. Since the member 43 is firmly fixed to the shaft 16, movement of the threaded shaft 54 therein causes the segment 32 to move toward and away from stationary arm 43. Tie bar 60, secured to the segments 32 and 34, hold them in fixed spaced relation so that when the segment 32 is moved axially, the segment 34 will necessarily move with it. Thus, by rotating the hand wheels 52 and 58, the mounting base 40 may be moved in two directions, i.e., radially and axially.

As pointed out above, the saddle is constructed in similar fashion to saddle 18 and may be moved with respect to the shaft 16 in the same manner. In order to move both saddles simultaneously while maintaining their established relationship to shaft 16, the shaft 16 is rotatably mounted in the upright frame members 12 and 14. The shaft may be rotated and locked against rotation by means of the stick member 62 which extends through the shaft at approximately the: center and makes contact with latch element 7 0, as best shown in Figure 3. Latch element 70 is pivotally mounted by means of the pin 72 on the block 75 secured to the underside of the shaft 16. An upright plate 66, fixed to the bed 10 by means of suitable brackets 68, as shown in Figure 1, contains an arcuate notch 67 in the top thereof. The notch follows the path which block takes as shaft 16 rotates. When the stick 62 is turned in the shaft, the threads on the lower end thereof which are engaged with cooperating threads in the lower portion of the shaft 16, cause the stick to move downwardly and engage the latch member 70, which pivots about pin 72 to bind the plate 66 against block 75. This prevents rotation of the shaft.

In order to be able to move simultaneously both saddles on shaft 16 back to a predetermined position from which they have been rotated, I have provided a stop 82 which takes the form of a pin (Figure 4). The stop is slidably mounted in opening 84 in block which is split, as indicated at 81. The split permits the block to clampthe stop 82 against movement through the opening. The block 80 is mounted on shaft 78 which extends across the machine parallel with shaft 16 and is rigidly fixed in uprights 12 and 14. A pair'of leaf springs 86 is dis posed one on either side of the stop 82 normally to urge the stop toward the shaft 16 into contact with the flat 32a on segment 32. The springs 86 are secured at their opposite ends to pins 88, 89. Pin 88 extends through the stop 82 and pin 89 extends through the block 80. When the saddle rotates rearwardly the face of the tie bar 60 contacts the end of the stop 82 and causes it to move rearwardly in the opening 84 against the compressive force of the springs 86. In order to mark the position to which the saddle is rotated, a locking means is provided consisting of an actuating shaft 90 having threads on the right end thereof which screw into complementary threads in the right half of the split portion of the block 80, as shown in Figure 4. A collar 91 is fixed to the shaft 90 and bears against the left half of the split portion; hence when the shaft 90 is rotated the split 81 in the block is closed to squeeze the stop 82. For actuating the rod 90 a handle 92 has been provided, as best shown in Figures 1 and 2. When the handle is turned to loosen the stop 82 and the saddle is rotated upwardly out of contact with the end of the stop the springs 86 will return the stop to its normal position.

For picking up and magnifying an image of a particular area of a plate mounted on the saddles 18 and 20, I provide a viewer, indicated generally by the numeral '24, mounted for axial movement on the shaft 22 which is journaled at either end in uprights 12 and 14. A, shoulder 103 (Figure 2) on the mount 102 bears .against the side of the frame member 26 which extends port 102 extends toward the front (right) of the machine and holds a cross bar on which are mounted identical scanners 95 and 96. The viewer contains a series of reflecting mirrors and prisms which are adapted to transmit an image from a plate mounted on eithersaddle upwardly through the viewing device to a ground glass screen 100. In order to illuminate the image area being optically transmitted to the screen, lamps 97 are provided above the scanners. The rays of light from the lamps radiate downwardly through the prism 98 onto the area which is to be transmitted. The viewer is of conventional construction, and need not be described in more detail for an understanding of the present invention.

In order accurately to locate the viewer axially with respect to the plate marking elements mounted on the machine, I provide an arm 106 which extends parallel to the bar 22 from the viewer support 102. The bar carries a head 108 in the form of a permanent magnet which is adapted to abut the ends of indexing stops 116. The magnet insures positive contact. Indexing stops 116 project from a disc 110 which is rotatably mounted 5 ll th llp ish .91 a ha t l bera e -tha flw adex st p r o en l n h Th i t ea ga m tl t va ious zed Plates w ch e to b re istered on the apparatus. The stops are intended to shei ses n a a t me n s q a c w t the si of the plate P on the saddle, and may be brought into alignment with the magnetic head 108 by rotating the shaft 112. A hand wheel 114 is provided on the end .of shaft 112 for this purpose. The construction of the indexing devices at either end of the apparatus are identical and consequently only one has been described. For left-hand pages the left-hand indexing stops are ,used, while the right-hand stops are used for right-hand pages. To prevent rotation of the indexing plate 110 except upon application of force to the hand wheel, a :detent '111 has been set in the upright frame member -and projects into spaced depressions in the face of the plate 110.

' The ground glass screen 100 has cross hairs or simi- -lar marks inscribed thereon which complement the indexing stops 116 in accordance with the size of the plate which is being registered. For example, if the plate is oversize the oversize index stop 116 is aligned with shaft 106 so that when the reference character on the plate is superimposed on the cross hairs marked over- Isize onthe ground glass screen 100, the plates are correctly placed with respect to the markers 130, 132 and 164, 165.

For'marking the plates after they have been brought into registration I employ cutting elements 130, 132 and 164, 165 which have sharp knives on the ends thereofcapable of scribing the electrotype plate. The marking devices 130, 132 are those which inscribe the axial marks lengthwise of the plate. These marking devices are adapted to move along a pair of parallel bars 134, 135 which extend along the entire length of the machine and are fixed at their ends in the uprights 12, 14. Each marking device is secured in its upper end to a carriage in the form of a ring 137 which slides along the bar 134, Figure 6. The ring is welded to a block 239 which slides on bar 135 and thus prevents rotation .of the markers 130, 132 with respect to bar 134.

To bring the cutting devices 130 and 132 into cutting engagement with the plate I have provided a pulley and cable arrangement which is best illustrated in Figure 8. A cable 153 is fixed at one end to the carriage 137 to which the marking device 130 is attached and is trained about the pulleys 151 (secured to block 239), 152, 150, .148, 146, 144 and extends from the pulley 144 into the interior of the hollow shaft 16. The pulleys are mounted on brackets fixed to the frame of the machine, as shown in Figures 1 and 2. The other end of cable 153 conmeets to the mechanism for applying the radial marks to the plate and will be described below. When the cable 153 is pulled the marking device 130 will move toward the one side of the saddle and the marker 132 will move toward the other side of the saddle until they strike the edges of the plate P to scribe the same. Force is applied to the cable 153 by means of a handle 138 which attaches to the take-up pulley 148 by means of another cable 155 trained around pulleys 139 and 141. Take-up pulley 148 rides up and down on a pair of guide rods ;12'1 fixed to the uprights 12, 14 at either end of the machine, Figure 2. In order to retract the mark-- ing device 132, I have provided a cable 140 having a weight 142 attached to the lower end thereof which cable is secured to the marking device 132 and is trained over pulleys 154 and 156. As soon as the handle 138 has been released the weight 142 pulls the marking de- -.vice 132 back to its original position. Marking device 130, integrally secured 'to pulley 151, is retracted by means of a separatecable 176 trained over pulleys 186, 18,8 and which carries a weight 190.

A similar arrangement is employed for moving the devices 164 and 165 which scribe the radial 6 m rk o t p a .Matk as d i .1 4 and 16. ar

mounted on arms and 166, respectively. flflre arm 160 terminates at its lower end in a circular pgrtion l62 having an opening therethrough surrounding the main shaft 16, Figure 6. Consequently,the arm 160 rotates about the shaft as a center. The arm 160 carries the marker 164 for the front edge of the plate, while arm 166 carries the marker for the rear edge of the plate. The end of arm 160 terminates in a right angular portion 169 by which the marker 164 is carried. This permi-ts markers 164 and to be in alignment while the arms are laterally spaced from each other on the shaft 16. It will be noted that the arm 166a, which cooperates with saddle 18 (left side), is extensible. This is to permit retraction of the arm to allow passage of the trimmer 124 as explained hereinbelow. The extension arm 170 slides axially of the ,arm 166a in a sleeve secured to the end of arm 166a, Fig. 2. A series of teeth 172 are formed in the upper edge of the arm 170 and a pinion 174, mounted on sleeve 175, rotates'with its teeth in mesh with the teeth 172 to cause the arm to extend and retract as desired. The pinion 174 is grooved so that it also serves as a pulley.

The end of the cable 153 is wound aroundthe pinion 174 a couple of times and as the cable is moved forward and backward the pinion is rotated to extend or retract the arm. Cable 153 is trained about pulley 178 which is rotatably mounted on the arm 160 and then encircles the pulley 180 above shaft 16, and pulley 182 inside the shaft 16. The cable emerges from the shaft and is directed upwardly about the pulley 144 as indicated previously. The arms 160 and 166 are mounted on shaft 16 intermediate the clamped upright members 42 and 43. An opening 38 is provided through the stop bar 36 fixed to the surface of the saddle to permit the cutting edge of the marker 164 to come into contact with the plate. This is best shown in Figure 6.

For retracting the arms 160 and 166a I have inserted compressions springs 200 between the arms which are compressed when cable 153 is tightened and when the cable is released springs expand, forcing arms 160 and 166a apart. Spring 171 connected to arm 170 at one end and .-to shaft 16 at the other end through stud 173 assists in retracting arm 170 when tension on cable 153 is released.

' The markers for the saddle 20 operate in exactly the same way except that there is no necessity for a retractable rear marking device since the trimming blade 124 is only used to trim plates which are mounted on the saddle 18.

For trimming the plate mounted on saddle 18, axiallydisposed guide means 118 in the form of a channel, which carries the cutter, is secured to a pair of arms 120 rotatably mounted on the main shaft 16 near either end thereof (see Figure 2). Thus the guide means may be moved up and down radially about the shaft for adjustment with respect to the edge of the plate P which extends over the saddle. An adjustable stud 128 extends from the bottom of the arm 120 and makes contact with the bed 10 to locate the guide means at the desired angle and height. The amount trimmed from the plates may be adjusted to provide bleed, regular or other sized plates. An electric motor 122 is bolted to a plate 125 which moves in guide means 118 and has a cutting blade 124 fixed to the shaft thereof. The plate 125 rides on roller bearings 126 disposed between the underside of the plate and the base of the guide means. Thus the motor and the cutting blade attached thereto may be pushed along the guide means to trim the edge of the plate which extends beyond the supporting saddle 18. This is the edge which abuts the stop fixed to the printing cylinder on which the plate is mounted. The other three edges are trimmed prior to the registering operation.

Although I have shown a cable and pulley arrangement for actuating the marking devices it will be understood that any other suitable means maybe employed 7 for this purpose. For example, pneumatic or hydraulic cylinders will serve very well to move these members inwardly or outwardly as required.

Practical operation In operating the version of the device shown in the drawings the plate to be registered, usually the black 'plate, is placed on the saddle 18 and clamped thereto by means of clamps 39 as shown in Figure 7, with one edge "of the plate abutting the stop 36 and the other edge (which is to be trimmed) extending beyond the saddle. The saddle mounting plate 40 is about a 90 segment. The viewer is setagainst the appropriate stop 116 at the side of the machine; for example, regular, oversize, bleed, depending upon the size of the plate. The lefthand stop is used for left-hand pages. Usually the page number (but any other indexing device can be used) is brought into view on the ground glass screen 100 by adjusting the location of the saddle 18 with respect to the scanner 96. The page number must coincide with cross hairs provided on the face of the ground glass screen. There are several cross hairs, one for each of the difierent size plates which are normally registered on the apparatus. These are marked regular, oversize, bleed, like the indexing stops 116. When the page number for an oversized plate has been brought into alignment with the cross hairs for that particular size plate, the plate is then centered precisely with respect to the marking devices 130, 132 and 164, 165. Alignment of the page number is accomplished by turning hand wheels 52 and 58. The plate is then marked by pulling the left-hand handle 138 which, through the cables and series of pulleys previously described, causes the markers 130 and 132 to move toward each other in the same manner as traverse draperies. The sharp cutting edges on the ends of the marking devices, which are disposed at the angle of the bevel on the edge of the plate, place a scribe mark in opposed edges of the plate. An imaginary line drawn from one scribe mark to the other defines the axial center line of the plate and will coincide with the axial scribe mark on the printing cylinder to which the plate will ultimately be secured.

Simultaneously with the application of the axial marks, the marking devices 164 and 165 apply scribe marks to the other two edges of the plate along a radial center line, since the left handle 138 actuates both sets of markers. The cutting blade on the end of the marker '164 makes contact with the plate through an opening 38 in the underside of the stop 36 (Fig. 6) against which the plate is mounted on the saddle 18. The other marking device 165 contacts the other edge of the plate, the arm 170 becoming extended against the tension of spring 171 by reason of the rotation of the pinion 174 by moving cable 153. Normally the arm 170 is retracted to permit trimming of the plate on the saddle 18, and this position is assumed after the handle 138 is released by action of spring 171. Spring 200 retracts the markers 164, 165 to normal position.

After the plate has been marked the cutting blade 124 is passed along the inner edge of the plate by moving the motor 122 along the previously adjusted guide 118 on roller bearings 126. Thus the edge of the plate is trimmed to the precise distance from the axial scribe marks required for the printing cylinder on which it will be mounted. There is a reference stop on the cylinder against which this trimmed edge abuts.

Before the saddle 18 is moved the stop 82 is released by turning the shaft 90 by means of handle 92. The end of the stop 82 under the influence of the springs 86 then abuts the face of the flat 32a. The shaft 90 is then rotated in the opposite direction to tighten the block 80 about the stop 82 so that it cannot move. Thus the radial location of the saddle 18 is fixed so that it can always be moved back to the original position. From this point on in the registering operation the saddle 18 is not moved 's with respect to main shaft '16. Radial movement'is accomplished by rotating the entire shaft 16 (and both saddles), but there is no further axial movement of the saddle.

The next step is to register the first color plate with the black reference plate mounted on saddle 18. The color plate has no page number thereon. The color plate, the edges of which have been previously trimmed, is mounted on the right-hand saddle 20 against the stop 36. The viewer is moved axially and the saddle 18 is moved radially as required to pick up a suitable image from the reference plate whichis readily identifiable as it appears on the ground glass screen. Radial movement is brought about by releasing latch 64 and pushing stick 62 back and forth to rotate both saddles on shaft 16. When the desired image appears the shaft 16 is locked against rotation. The saddle 20 is then moved both radially and axially as required to bring the same image into precise superimposition with the image picked up by the scanner 96 from the reference plate. This is done by moving the saddle 20 with hand wheels 52, 58. The shaft 16 remains fixed during the adjustment of saddle 20, by latching with latch 64. When the two images are in precise alignment so that they appear as one, the plates are registered one with the other. Now it is necessary to bring the two aligned plates back to the original adjusted position of the reference plate. This is done by releasing the latch 64 and rotating the shaft 16 back to the position sensed by the fixed stop 82. As soon as the tie bar 60 comes in contact with 'the stop 82 the shaft and the saddle 18 are once again in their original positions. This brings saddle 20 into correct working position. Now the right-hand handle 138 can be pulled to apply the scribemarks to the color plate in the same manner as previously described in marking the reference plate. The color plate thus becomes scribed with four marks which are aligned with the axial lines on the printing cylinder and the center of the streamers.

The second color plate is then mounted on the saddle 20 and registered with the black reference plate in exactly the same way as the first color plate. Thus the yellow, red and blue color plates are each registered in turn so that we have very accurate registration with respect to the reference plate.

In marking bleed or oversize reference plates it is necessary, of course, to adjust the stops 116 so that they are set for that particular size plate. On the bleed or oversize plates the predetermined reference mark such as the folio is found in a different location with respect to the edges of the plate from that on a regular size plate. It is also necessary to align the folio with a different cross hair which is identified on the ground glass screen in accordance with the size of the plate.

It will be understood that the page number reference is merely used for purposes of illustration. Any suitable standard figure on the reference plate will serve just as well. The location of the trimming saw, the viewer and the marking knives, of course, will have to be coordinated with any such mark to insure accurate marking.

Other modifications in the construction of the machine will become apparent to those skilled in the art from the disclosure herein. It is, therefore, my intention not to restrict my invention to the particular forms shown and described otherwise than as necessitated by the scope of the appended claims.

What is claimed is:

1. Apparatus for registering printing plates which comprises a first support for mounting a reference plate and a second support for mounting a plate to be registered with said reference plate, said supports being mounted for axial and radial movement on a single shaft, a frame upon which said shaft is rotatably mounted, a carrier bar fixed to said frame above said shaft and parallel thereto, a viewer mounted for axial movement along said carrier bar including a pair of scanners one over each said support and a screen for viewing the image sensed by said scanners, and means for applying registering indicia to printing plates mounted on said supports.

2. The apparatus of claim 1 which also includes stop means carried by said frame for limiting the rotation of said shaft in one direction.

3. Apparatus for registering printing plates which comprises a frame including a pair of spaced upright members, a shaft rotatably mounted in said upright members, a first saddle forsupporting a reference plate and a second saddle for supporting a plate to be registered with said reference plate mounted for axial and radial movement on said shaft, adjustable stop means carried by said frame for limiting rotation of said shaft in one direction, a carrier far fixed to said upright members above said shaft and parallel thereto, a viewer mounted for axial movement along said carrier bar including a pair of scanners, one over each saddle, and a screen for viewing the images sensed by said scanners, indexing means on said frame for locating said viewer with respect to said saddles, and means carried by said frame adjacent said saddles for applying registering marks to printing plates on said saddles.

4. The apparatus of claim 3 wherein said indexing means is adjustable to accommodate different size printing plates and said viewing screen carries marks which in cooperation with predetermined marks on said reference plate locate said different size plates with respect to said marking means.

5. The apparatus of claim 3 which also includes a trimmer for trimming one edge of said reference plate, said trimmer being mounted for axial movement on guide means pivotally secured to said shaft.

6. The apparatus of claim 3 wherein said marking means comprises two pairs of knives adapted to scribe opposed edges of said plates, said first pair being carried by said frame and adapted to move axially of said shaft, and said second pair being mounted for rotation about said shaft.

7. The apparatus of claim 6 which includes actuating means supported by said frame for moving said marking knives into contact with the edges of said plates and for retracting them.

8. The apparatus of claim 3 which includes a latch for locking said shaft against rotation in a predetermined position, and means secured to said shaft for rotating same.

9. Apparatus for registering printing plates which comprises a frame including a pair of spaced upright members, a shaft rotatably mounted in said upright members, a first saddle for supporting a reference plate and a second saddle for supporting a plate to be registered with said reference plate mounted for axial and radial movement on said shaft, stop means carried by said frame for limiting rotation of said shaft in one direction, a carrier bar fixed to said upright members above said shaft and parallel thereto, a viewer mounted for axial movement along said carrier bar including a pair of scanners, one over each saddle, and a screen for viewing the images sensed by said scanners, means carried by said frame adjacent said saddles for applying registering marks to printing plates on said saddles, a latch for locking said shaft against rotation in a predetermined position, and means secured to said shaft for rotating same.

References Cited in the file of this patent UNITED STATES PATENTS 736,968 Faeber Mar. 6, 1956 

